The flash memory cards, such as compact flash (CF) cards, smart media cards (SMC), multimedia cards (MMC), secure digital (SD) cards, and memory sticks (MS), are used in a wide range of electronic products, including mobile phones, MP3 players, digital cameras, and so on. The durability and the waterproof are important issues for the design of the structure for memory cards. Taiwan Patent Application No. 94146117 disclosed a structure and method for packaging a memory card. A circuit substrate is placed on a bottom shell, and partially covered with a top shell. An insert molding with the same material as the bottom shell and a top shell is used to seal the bottom and top shells to form a monolithic memory card. The disclosed structure provides enhanced strength and improved waterproof. The inventor of the above disclosed invention continuously seeks to provide an even more improved structure for memory cards.